Question: Who was Max Planck's assistant?
Paraphrase: Who was Max Planck's assistant?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P184 wd:Q9021 . ?sbj wdt:P31 wd:Q5 } 
Answer: Walter Gordon, Walther Bothe, Erich Kretschmann, Richard Becker, Erich Schumann, Julius Edgar Lilienfeld, Hilde Heinicke, Heinrich Karstens, Karl Körner, Isidor Israel Malkin, Wilhelm Wenzel, Karl Erich Hupka, Max von Laue, Gustav Ludwig Hertz, Moritz Schlick, Walter H. Schottky, Walther Meissner, Max Abraham